is true, and the second false, we learn by experience, and by that
alone; just as we learn the like in regard to the phenomena of the
material world. Indeed, the fact that human volitions are both
predictable and modifiable, quite as much as all those physical
phenomena that depend upon a complication of causes--which is only a
corollary from what has just been said--is so universally recognized and
acted upon by all men, that there would probably be little difference of
opinion about this question, if the antithesis were not obscured and
mystified by the familiar, but equivocal, phrases of Free-will and
Necessity.

Passing over chapter xxvii., in which Mr Mill refutes Sir W. Hamilton's
opinion that the study of mathematics is worthless, or nearly so, as an
intellectual discipline--we shall now call attention to the concluding
remarks which sum up the results of the volume. After saying that he
'differs from almost everything in Sir W. Hamilton's philosophy, on
which he particularly valued himself, or which is specially his own,'
Mr Mill describes Sir W. Hamilton's general merits as follows:--

'They chiefly consist in his clear and distinct mode of
bringing before the reader many of the fundamental questions
of metaphysics: some good specimens of psychological
analysis on a small scale: and the many detached logical and
psychological truths which he has separately seized, and
which are scattered through his writings, mostly applied to
resolve some special difficulty, and again lost sight of. I
can hardly point to anything he has done towards helping the
more thorough understanding of the greater mental phenomena,
unless it be his theory of Attention (including
Abstraction), which seems to me the most perfect we have;